New York: The different allergy labels in common use may be confusing consumers instead of helping them decide whether to buy a food product, a new Canadian study shows.

"We should narrow (various allergy labels) to only one which will be clear," said Dr. Moshe Ben-Shoshan, a professor of allergy and immunology at McGill University Health Center in Montreal, who worked on the study.

An estimated 2.5 million Canadians and 15 million Americans suffer from food allergies, which can cause reactions ranging in severity from itchiness and vomiting to breathing problems, loss of consciousness and even death. Allergy labels are governed in the U.S. by the Food Allergen Labeling and Consumer Protection Act of 2004, and in Canada by the Food Allergen Labelling Regulations, a new version of which will go into effect in August.

Although all these labels warn that a product could harm a person with allergies, they present that message in various ways. Researchers found that some labels are less effective than others in helping consumers to avoid potentially dangerous foods.

Ben-Shoshan's team recruited more than 2,400 subjects from the general public and from allergy registries and advocacy groups for the new study, conducted between May 2007 and March 2009. The work was funded by Health Canada, a federal agency, and AllerGen, a network of allergy experts, and published in a letter to the editor in the Journal of Allergy and Clinical Immunology.

The participants included "directly affected" households in which at least one family member had a food allergy, as well as "indirectly affected" households which supply food to others with allergies such as students and preschoolers.

They answered questions about their likelihood of buying a food product depending upon various types of allergy alerts, including "may contain" foods to which people are allergic, "manufactured in a facility" that processes such foods, and "not suitable" for people with food allergies.

Researchers found people were more likely to ignore warning labels if their households were directly rather than indirectly affected by food allergies. Those who belonged to advocacy groups were most vigilant about their food purchases.

About 44 percent of directly affected consumers from the general public said they would buy a product which warned it "may contain (peanut/tree nut/sesame)." Only about 10 percent of those recruited from allergy associations, and 16 percent of consumers indirectly affected by food allergies, said they would buy a product with this label.

Across all groups, the "not suitable" label had the greatest effect in preventing purchase of a product. Participants in households were less vigilant if only adults had a food allergy than if a child had an allergy.

TAKING MORE PERSONAL RISKS?

The finding that consumers were less diligent about heeding labels when buying for their own households surprised researchers, said Ben-Shoshan.

"They may feel more responsibility when preparing food for other people," he explained. Food purchases for an allergic person in one's own household are also made much more frequently, which might make it harder to exercise caution, he added.

Adults may indeed take more chances with their own health than they would if the food allergy involves a child or someone outside their household, agreed Dr. Rauno Joks, chief of allergy and immunology at SUNY Downstate Medical Center in Brooklyn.

"They think they can get away with a certain amount (of restricted foods) before having a reaction. I really caution them not to take chances with their health. The greater motivation to heed allergy labels among advocacy group members highlights the need for more awareness. The more educated people are, the more likely they are to be proactive in avoiding food allergens," said Joks, who was not involved in the study.

The findings in Canada should apply to the United States, given their similarities in labeling standards and public awareness, he added. The disorder appears to be on the increase in several countries, especially among children. According to a 2008 study by the Centers for Disease Control and Prevention, the rate of food allergy rose 18 percent among children between 1997 and 2007.